This application is a 371 of PCT/FR02/03454, filed Oct. 10, 2002
The present invention relates to the field of anchoring safety, for example for people working high up on roofs of buildings or on other structures.
To ensure the safety of individuals, in particular those working on roofs, the worker is provided with a harness and a tie that he connects to an anchoring device. In the event of a fall, it is this anchoring device, fastened to a receiving structure, for example the roof, which checks the fall.
Such an anchoring device must be able to limit the height of a person's fall as far as possible and induce a minimum amount of force on the receiving structure.
In certain cases, the receiving structure does not have sufficient strength to withstand large forces, such as during a fall, for example. It is therefore essential in those cases for the anchoring device to have an energy-absorbing capability, operating as it were as a shock absorber.
It is also necessary, when the anchoring device is being fastened to the receiving structure, for example a roof, to ensure that said roof is sealed. This problem arises in particular in the case of anchoring devices fastened directly to the framework and passing through the roof covering. The fact that the sealing function of the roof covering has to be restored after the anchoring device has been installed obviously adds significantly to the cost of the work undertaken.
Fastening anchoring devices directly to the roof covering presents not only problems of resistance to forces but also problems connected with variable forms of the roof coverings.
Known anchoring devices often have shock-absorbing means which need to be calibrated so that they can withstand a shock or a pull whose intensity is above a certain threshold.
Developing such anchoring devices is very difficult and requires a high number of tests for each intended use. It is thus necessary to ensure that the shock-absorbing means do not activate when subjected to a stress below a predetermined intensity on the one hand and that this adjustment does not negatively affect the level of absorption on the other hand.
It may be difficult to be able to reconcile the parameters and the tests do not generally allow verification to be carried out without irreversibly damaging the anchoring device.
The term “roof covering” is intended to mean any roof covering, and in particular corrugated steel sheeting, for example with a trapezoidal profile.